BIO203 Final Term Mega File by Biotech Brainy Bunch

SHORT QUESTIONS

Qno1: Difference between Blotting Technique on basis of detection.

SOUTHERN BLOTTING:

The Southern blot is used to detect the presence of a particular piece of DNA in a sample by a

NORTHERN BLOTTING:

Northern blot is a method used for detection of a specific RNA sequence in RNA samples.

Qno2: Write down the limitations of Western blotting?

•  A minute imbalance at any level blotting of the procedure can skew the results of the entire process.
•  Incorrect labeling of the protein can happen due to the reaction of secondary antibody.
•  erroneous in bands or no bands due to insufficient transfer.
•  Well trained technicians are required for this technique.
•  Primary antibody availability is crucial.
•  It is just a semi-quantitative at best. Only an approx. estimation & not a precise measurement of molecular weight of the protein are possible.

Qno3: Nomenclature of enzyme.

GROUP: BIOTECH BRAINY BUNCH · ALL DATA FROM PAST PAPERS (2017-2022) · ADMINS: MEHWISH MUGHAL & BELLA

A suitable system was proposed by Smith and Nathans (1973).

•  The species name of the organisms is identified by the first letter of genus and first two letters of specific epithet like E.coli = Ecoli.
•  Strain identification is written as EcoK.
•  In case, host strain has several restriction and modification systems, these are identified by roman numerals, for example, in case of H. influenzae. Like HindI, HindII, HindIII etc.
•  All restriction enzymes have general name endonuclease R and modification-methylase M. Followed by the system name, for example, in case of H. influenzae
•  R. HindIII or M. HindIII.

Qno4. Write properties of probes?

PROBES

•  Labeled material to detect a target.
•  For DNA: 20-30 nucleotides
•  complementary to a region in the gene or DNA.

Qno5: Write applications of PCR in clinical microbiology.

PCR-Medicine

•  PCR has major impact on medicine especially in the field of clinical microbiology or diagnosis.
•  Molecular tools have also allowed performing prenatal genetic diagnosis.

Qno6: Explain R-M system.

Types of restriction and modification (R-M) system

At least 4 R-M system are known.

•  Type-I
•  Type-II
•  Type-III
•  Type-IIs

Type I

Type I were the First to be characterized from E. coli K12. The active enzyme consists of two restriction subunit, two modification subunit and one recognition subunit. Type I are of little value for gene manipulation.

Type II

Most of the useful R-M system is Type II. Type II R-M system recognize a defined sequence and cut within it.

Type III

Type III enzymes have symmetrical recognition sequences but otherwise resemble type I systems and are of little value.

Type IIs

Type IIs systems have similar cofactors and structure to type II but restriction occurs at a distance from recognition site that limits their usefulness.

Qno7: Define SNP.

Qno8: Write down method of DNA Finger printing.

Types of DNA fingerprinting methods are

• Electrophoresis.
• Polymerase chain reaction (PCR).
• Restriction fragment length polymorphism (RFLP).
• Random Amplified Polymorphic DNA (RAPD).
• Amplified fragment length polymorphism (AFLP).

Qno9: Explain Western Blotting.

Procedure

•  Western blots have become one of the most common analytical tools for the detection of viral proteins.
•  Characterization of monoclonal and polyclonal antibody preparations and in determining the specificity of the immune response to viral antigens.